Re: Backtraces in Guile 2.0

[Andy Wingo <wingo@pobox.com>]

Hi Mike,

On Tue 22 Feb 2011 04:23, Mike Gran <spk121@yahoo.com> writes:

>   (symbol->string "STRING")
>
>    In module/ice-9/boot-9.scm:
>    1917: 3 [save-module-excursion #<procedure 14f3180 at module/ice-9/boot-9.scm:3341:3 ()>]
>    3348: 2 [#<procedure 14f3180 at module/ice-9/boot-9.scm:3341:3 ()>]
>    In unknown file:
>       ?: 1 [load-compiled/vm "/home/mike/.cache/guile/ccache/2.0-LE-8-2.0/home/mike/Documents/code/guile_backtrace/symbol1.scm.go"]
>       ?: 0 [symbol->string "STRING"]

Here, there is no procedure in the call chain that has source
annotations corresponding to symbol1.scm.  Though, it does seem to me
that the load-compiled/vm line is unnecessary; instead we should load up
the .go into a thunk, and run that thunk without recursing through the
load-compiled/vm primitive.

In any case it seems that symbol1.scm.go tail-calls symbol->string, so
we are left without source info.  Bummer.  We could improve this by
keeping a ring buffer of previous frames, like JRM suggests in
http://funcall.blogspot.com/2009/05/you-knew-id-say-something-part-iv.html.

Regards,

Andy
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